15h30 - 15h55
A Solution Framework for the Capacitated Multi-Commodity Fixed-Cost Network Design with Design-Balance Constraints
We study a class of the capacitated multi-commodity fixed-cost network design where the design-balance constraints are included. We propose a solution framework which is based on tabu-search, path-relinking and a weighted intensification scheme. The computational results indicate that the framework performed well on bench-mark instances, and are competitive with CPLEX and the current state-of-art tabu-search solution method for this problem.
15h55 - 16h20
Capacitated Hub-and-Spoke Network Design with Stochastic Demand and Congestion
In this talk, we present model and solution approaches for designing a capacitated single allocation hub-and-spoke network with stochastic demand and congestion. The problem is setup as a network of spatially distributed M/G/1 queues and modelled as nonlinear mixed interger program. We present computational results and insights.
16h20 - 16h45
Strategies for Designing Routes to Urban Garbage Collection
We consider three different routing design strategies to urban garbage collection: Route-First-Cluster-Second, Cluster-First-Route-Second and Route-Cluster-Route. The first strategy has been studied by the literature, and applies this concept by aggregating required street segments after designing a great route. This approach does not consider that the departure place of vehicles and disposal site are in different location, than intermediate facilities and the network are not considered before routing. The second approach is more susceptible to the practical design of different origin-destination routes, but needs more preparation in the stage of clustering the street segments to be covered. Finally the third, although more related to most recent CARP methodologies and costs normaly less, it has difficulties in the real life absorption by the managers and drivers. We show these strategies applied in routing over urban garbage collection street networks for the city of Fortaleza/CE, Brazil. We verify that for the different contexts (type of the street network, distribution of the garbage across the area) the design of the routes can achieve interesting results in presence of balanced or non balanced routes.